This infographic from Quicksprout proposes a wealth of tips on how to get your first 100 twitter followers.
For example:
If you are a content creator you can follow Jeff Bullas technique who has gained hundred of new Twitter followers within a span of 5 weeks through guest blogging.
BeardBrand increased its Twitter following by 1,500 percent through Twitter giveaways.
Ann Tran used "Be an informer, not a Meformer" strategy to grow her Twitter following from 0 to 400K.
Take a look at this visual for more Twitter follower growth strategies.